Surgical Indications for Hepatocellular Carcinoma with Non-hypervascular Hypointense Nodules Detected by Gd-EOB-DTPA-Enhanced MRI

Liver Lesions at Risk of Transformation into Hepatocellular Carcinoma in Cirrhotic Patients: Hepatobiliary Phase Hypointense Nodules without Arterial Phase Hyperenhancement

Recent technical advances in liver imaging and surveillance for patients at high risk for developing hepatocellular carcinoma (HCC) have led to an increase in the detection of borderline hepatic nodules in the gray area of multistep carcinogenesis, particularly in those that are hypointense at the hepatobiliary phase (HBP) and do not show arterial phase hyperenhancement. Given their potential to transform and advance into hypervascular HCC, these nodules have progressively attracted the interest of the scientific community. To date, however, no shared guidelines have been established for the decision management of these borderline hepatic nodules. It is therefore extremely important to identify features that indicate the malignant potential of these nodules and the likelihood of vascularization. In fact, a more complete knowledge of their history and evolution would allow outlining shared guidelines for their clinical-surgical management, to implement early treatment programs and decide between a preventive curative treatment or a watchful follow-up. This review aims to summarize the current knowledge on hepatic borderline nodules, particularly focusing on those imaging features which are hypothetically correlated with their malignant evolution, and to discuss current guidelines and ongoing management in clinical practice.

Gadoxetate-Enhanced MRI as a Diagnostic Tool in the Management of Hepatocellular Carcinoma: Report from a 2020 Asia-Pacific Multidisciplinary Expert Meeting

Gadoxetate magnetic resonance imaging (MRI) is widely used in clinical practice for liver imaging. For optimal use, we must understand both its advantages and limitations. This article is the outcome of an online advisory board meeting and subsequent discussions by a multidisciplinary group of experts on liver diseases across the Asia-Pacific region, first held on September 28, 2020. Here, we review the technical considerations for the use of gadoxetate, its current role in the management of patients with hepatocellular carcinoma (HCC), and its relevance in consensus guidelines for HCC imaging diagnosis. In the latter part of this review, we examine recent evidence evaluating the impact of gadoxetate on clinical outcomes on a continuum from diagnosis to treatment decision-making and follow-up. In conclusion, we outline the potential future roles of gadoxetate MRI based on an evolving understanding of the clinical utility of this contrast agent in the management of patients at risk of, or with, HCC.

Hypervascular transformation of hepatobiliary phase hypointense nodules without arterial phase hyperenhancement on gadoxetic acid-enhanced MRI: long-term follow-up in a surveillance cohort

OBJECTIVES

With the increasing use of gadoxetic acid-enhanced MRI for HCC surveillance, hepatobiliary phase (HBP) hypointense nodules without arterial phase hyperenhancement (APHE) are frequently encountered. We investigated the rate of these nodules with hypervascular transformation, which suggests hepatocarcinogenesis, by using a prospectively collected longitudinal surveillance cohort data.

METHODS

This study included 382 prospectively enrolled patients at high risk for developing HCC who underwent 1-3 rounds of bi-annual surveillance gadoxetic acid-enhanced MRI. MRI was analyzed to detect HBP hypointense nodules without APHE. Follow-up dynamic CTs and MRIs were evaluated to detect hypervascular transformation of the nodules. Cox proportional hazards regression analyses were used to find predictors for hypervascular transformation.

RESULTS

A total of 76 HBP hypointense nodules without APHE were found in 48 patients, giving a prevalence of 12.6% (48/382). The mean nodule size was 10.8 mm, with 43.4% (33/76) being ≥ 10 mm. Over a median follow-up of 78.6 months, 19 nodules (25.0%) showed hypervascular transformation, all of which demonstrated typical imaging features of HCC. On multivariable Cox-regression analysis, size (≥ 10 mm) was the only independent predictor of hypervascular transformation (hazard ratio, 3.31; 95% confidence interval, 1.21-9.05). The cumulative incidence of hypervascular transformation at 12 and 60 months of nodules ≥ 10 mm was 12.3% and 50.4%, respectively, while that of nodules < 10 mm was 2.5% and 13.9%, respectively.

CONCLUSIONS

About half of the HBP hypointense nodules ≥ 10 mm without APHE transformed to HCC at 5 years of follow-up, indicating the necessity for cautious monitoring with an augmented and extended follow-up schedule for these nodules.

KEY POINTS

• The prevalence of HBP hypointense nodules without APHE was 12.6% in a prospectively recruited population at high risk of developing HCC. • Nodule size ≥ 10 mm was significantly associated with hypervascular transformation, and approximately half of the HBP hypointense nodules ≥ 10 mm without APHE transformed to HCC during 5 years of follow-up. • Given the risk of malignant transformation, HBP hypointense nodules ≥ 10 mm without APHE should be closely monitored.

Prognostic Impact of Vessels that Encapsulate Tumor Cluster (VETC) in Patients who Underwent Liver Transplantation for Hepatocellular Carcinoma

BACKGROUND

There is limited published information about prognostic value of vessels that encapsulate tumor cluster (VETC) based on their involvement with immune cells in hepatocellular carcinoma (HCC). Our goal was to evaluate prognostic impact of VETC in patients who underwent living-donor liver transplantation (LDLT) for HCC, focusing on the involvement of VETC with immune status in tumor microenvironment (TME).

METHODS

Using a database of 150 patients who underwent LDLT for HCC, immunohistochemical staining of CD34 for VETC, angiopoietin-2 (Ang-2), CD3, and CD68, was reviewed with patients' clinicopathological factors.

RESULTS

A strong correlation between VETC pattern and malignant potential in HCC was observed; larger tumor size (P < 0.001), more numbers of tumors (P = 0.003), higher α-fetoprotein levels (P = 0.001), higher des-γ-carboxy prothrombin levels (P = 0.022), microvascular invasion (P < 0.001), and poor differentiation (P = 0.010). Overall survival (OS) of patients with VETC⁽⁺⁾ was significantly lower than those with VETC^(-) (P = 0.021; 5-year OS rates, 72.0% vs. 87.1%). Furthermore, the ratio of CD3⁽⁺⁾ cells was significantly lower in VETC⁽⁺⁾ group (P = 0.001), indicating that VETC activity may be strongly correlated with lymphocyte activity. Moreover, combination status of VETC⁽⁺⁾/CD3^low was an independent risk factor for mortality (hazard ratio 2.760, 95% confidence interval 1.183-6.439, P = 0.019). Additionally, the combination of VETC expression with immune status (low CD3 levels) enabled further classification of patients based on their clinical outcome.

CONCLUSIONS

Our results show the prognostic impact of VETC expression, tumor-infiltrating lymphocytes (TILs), and their combination in the setting of LDLT for HCC, which can be a novel prognostic biomarker for mortality after LDLT.